An ink jet printer has a removable print cartridge with a reservoir therein to hold a supply of ink to produce printing. When the ink in the reservoir is exhausted, it is necessary to replenish the supply of ink.
Instead of using a new print cartridge as a replacement to replenish the ink supply, it has previously been suggested to refill the reservoir in the print cartridge with ink. Previously suggested means for refilling the reservoir in the print cartridge include a squeeze bottle and a syringe having a movable plunger. Each of U.S. Pat. No. 4,419,677 to Kasugayama et al and U.S. Pat. No. 4,589,000 to Koto et al shows the use of a plunger in a syringe for refilling a reservoir of a print cartridge.
Each of the squeeze bottle and the plunger in the syringe has the disadvantage of requiring the user to exert a force to supply ink to the reservoir. Depending on the force exerted by the user, ink can flow too quickly for the porous material in the reservoir to absorb; this results in frequent overflow of ink. This ink overflow usually results in spillage and necessitates cleaning up the spillage. As a result, users are not favorably disposed towards using the previously suggested refill devices.
The reservoir of a print cartridge may be partially or completely filled with a porous material such as foam, for example, as shown in U.S. Pat. No. 4,771,295 to Baker et al and U.S. Pat. No. 4,999,652 to Chan. The use of the porous material creates a capillary action to cause ink to flow into the reservoir with the aforesaid Baker et al patent having a foam of a controlled porosity. The aforesaid Chan patent uses a complex arrangement for continuously supplying ink to the reservoir from a removable bottle.